Process for fissuring acoustical fiberboards



April 23, 1963 E. A. LAURING 3,

PROCESS FOR FISSURING ACOUSTICAL FIBERBOARDS Filed Nov. 1. 1960 2 Sheets-Sheet 1 INVENTOR. EDGAR A. LAU RING 2 Sheets-Sheet 2 INVENTOR EDGAR A. LAURING E. A. LAURING FIG. 4

FIG. 5

April 23, 1963 PROCESS FOR FISSURING ACOUSTICAL FIBERBOARDS Filed Nov. 1. 1960 United States Patent 1 3,086,878 PROCESS FOR FISSURING ACOUSTICAL FIBERBOARDS Edgar A. Lauring, International Falls, Minn, assignor to Minnesota and Ontario Paper Company, Minneapolis,

Minn.

Filed Nov. 1, 19613, Ser. No. 66,459 2 Claims. (Cl. 117-8) This invention relates to a method of imparting certain desirable characteristics to a board form material from fibers.

One of the objects of this invention is the method of treating fiberboard to provide a decorative surface and at the same time provide improved sound-absorbing units.

It is a further object of the invention to produce a fissured board or tile by a method which is simple, economical, and practical.

Other objects and advantages of the invention will become apparent as the description of the same proceeds, and the invention will be understood from a consideration of the following description taken in connection with the accompanying drawings forming a part of the specification, that the invention is not to be limited to the exact details shown and described, since obvious modifications will occur to a person skilled in the art.

In the drawings:

FIGURE 1 is a diagrammatic View illustrating equipment useful in carrying out certain steps of the method;

FIGURE 2 is a plan view of a tile blank which has been treated to provide random arranged fissures;

FIGURE 3 is a plan view of a tile blank which has been treated as indicated in FIGURE 1, but has been further treated to provide random needlelike openings;

FIGURE 4 is a sectional view on an enlarged scale, taken along line 3-3 of FIGURE 3; and

FIGURE 5 is a view of a ceiling showing the arrangement of four tile units.

A variety of materials may be used to form the base board from which the tile blanks are cut. The base material may be lignocellulose fiber, mineral fibers, synthetic fibers, or a combination of two or more of these fibers. It is to be understood that the tile of the invention need not necessarily be an acoustical tile, but may be merely a decorative tile and this in part will depend upon the sound-absorbing properties of the base board.

The base board of whatever type employed is coated with any suitable materials, such as that shown in US. Patent No. 2,813,046. Whatever coating is applied to the base board it is preferred that at least two coats be applied and three coatings as shown in the patent referred to is highly desirable.

After the coating has dried, the tile blanks have fissures shown in FIGURE 2 punched into the surface of the board. The fissures penetration into the board 12 depends in part upon the thickness of the tile blank. So that the fissures may vary in depth from tile to tile, the equipment shown in FIGURE 1 is employed.

The coated tile blanks to be processed according to this invention may be of suitable surface area and suitable depth, such as 12 inches by 12 inches and /2 of an inch thick.

Many features enter into the selection of the density of a iignocellulose sound-absorbing tileboard. A density of 14 to 18 pounds per cubic foot gives excellent results where wood fiber tileboard is to be used.

The board after being coated, dried, and divided into tile blanks is placed in the apparatus shown in FIGURE 1 and the random air-ranged fissures 10 are pressed into the board 12. The depth of the fissures 10 vary in each tile as the embossing plate 30 with punches 44 relative position is varied by screw 28 on connecting rod 26. The depth of fissures from tile to tile difier in depth due to relative position of the embossing plate which is continuously changed. After the coated tile has been treated as shown in FIGURE 2, there is punched into the coated surface random arranged openings. The openings are of an order of to A3 cross-sectionally considered and extend from the front of the board about half way to the back of the board. It is to be understood that the openings may extend inwardly of the board as far as possible without completely perforating the board through the back. The tile as shown in FIGURE 3 has the surface spnay coated. The sprayed coating covers the board surface :and bottom of the fissures but not the sides thereof.

The openings 14 may be formed by apparatus similar to that shown in U.S. Patent No. 2,355,454, but in a random arrangement.

Coated tileboard blanks are fed, by any suitable means, to the apparatus shown in FIGURE 1, where the fissures 10 are punched into the boards 12. The depth of fissure penetration from the surface of the board depends in part on the sizes of the punches, the thickness of the tile blank, and the position of the punching head. The equip ment shown in FIGURE 1 includes frame member 16 with tile supporting base 17. Supported by frame 16 is shaft 18, carrying fly wheel 19 at one end and eccentric crank 20 at the other end. Carried by eccentric crank 20 is upper part of ram 22. To the upper part of ram 22 is attached gear reducer 24 which is operatively connected to the lower ram part 26. The lower ram part 26 is screw threaded at 23 so that the position of the press head can be varied.

To permit continuous change in the position of press head 39 there is provided a shaft 32 connected to the gear reducer and to a hydraulic motor 34. The direction of rotation of the shaft 32 is controlled by the direction of rotation of the motor 34. A timing switch 36 is operatively connected to the hydraulic motor 34 so that at a predetermined number of revolutions the direction of rotation of motor 34 is reversed. An adjusting screw 353 permits the controlling of the time of reversal of the motor 34. The timing switch 36 operating through relay switch 39 controls through hydraulic reversing valve 40 the direction of hydraulic fluid to motor 34 and thus the direction of rotation.

This may be accomplished through a relay switch which is electrically connected to the timing switch and to a source of power (not shown). Relay switch is in turn connected to the reversing valve 40. By way of example, the timing switch is said to reverse the hydraulic motor after a definite number of revolutions. If the hydraulic motor is arranged to lower the head for 15 turns of the shaft 32 and the hydraulic motor is running at 30 rpm, the motor would make a complete cycle every minute. If the press is pressing 30 tile per minute the 30 tile would be punched with 15 variation depths of depression, and since the punching heads have different lengths of punches, many variations in tile appearance are provided.

Pressing head 30 which move upwardly and downwardly in guides 42 has random arranged fissuring punches 44 thereon. The punches 44 are of varying length so that on each tile the depth of fissures vary.

In FIGURE 5 is shown a part of a ceiling with tileboard suitably secured to members 46. The fissures 10 are of varying depth on each tile and the direction as regards a given edge, in which the fissures extend vary from tile to tile. Fissue depth and direction in which they extend combine to provide a decorative ceiling having good sound-absorbing qualities.

What is claimed:

'1. In a method of fabricating a series of lignocellulose sound-absorbing units having decorative surfaces, consisting of applying a film forming coating composition to a series of lignocellulose fiberboards, drying the coating composition, mechanically punching openings through the coating and into the fiberboards, continuously varying the position of the mechanical punching means relatively to consecutive fiberboards of the series to vary the depth of the openings in the said consecutive fiberboards of the series and thereafter applying a coating composition to the fiberboard surface and to the bottom of the openings.

2. In a method of fissuring a series of lignocellulose fiberboards to provide decorative and sound-absorbing units having varying depth of fissures, consisting of coating a series of lignocellulose fiberboards with at least two separate applications of film forming coating composition, drying each application of coating composition applied to the fiberboard prior to the next application of the coating composition, mechanically punching openings through the coatings and into the fiberboards, continuously varying the position of the mechanical punching means rela- References Cited in the file of this patent UNITED STATES PATENTS 2,791,289 Proudfoot et al May 7, 1957 2,813,046 Lauring Nov. 12, 1957 2,874,796 Eckert Feb. 24, 1959 3,008,257 Landgraf Nov. 14, 1961 3,013,937 Brown et al. Dec. 19, 1961 OTHER REFERENCES Armstrong: Acoustical Ceilings, 1959, page 7. 

1. IN A METHOD OF FABRICATING A SERIES OF LIGNOCELLULOSE SOUND-ABSORBING UNITS HAVING DECORATIVE SURFACES, CONSISTING OF APPLYING A FILM FORMING COATING COMPOSITION TO A SERIES OF LIGNOCELLULOSE FIBERBOARDS, DRYING THE COATING COMPOSITION, MECHANICALLY PUNCHING OPENINGS THROUGH THE COATING AND INTO THE FIBERBOARDS, CONTINUOUSLY VARYING THE POSITION OF THE MECHANICAL PUNCHING MEANS RELATIVELY TO CONSECUTIVE FIBERBOARDS OF THE SERIES TO VARY THE DEPTH OF THE OPENINGS IN THE SAID CONSECUTIVE FIBERBOARDS OF THE SERIES AND THEREAFTER APPLYING A COATING COMPOSITION TO THE FIBERBOARD SURFACE AND TO THE BOTTOM OF THE OPENINGS. 